Variables are values that can be set globally for a given layout. They’re prefixed with a $ for easy reference (e.g. $my_global_var) and can be set to any valid string, number, or boolean value.

Open the sidebar's Variables tab to view, add, and update variables.

variables tab

Certain panels like the 3D and Variable Slider panels have built-in ways to update variable values with user interactions. Panels that support message path syntax – like Raw Messages, Plot, and State Transitions – can reference variables to dynamically decide what to visualize.

You can leverage variables to quickly switch between subsets of your data – for example:

  • Create a $my_ID variable in the Variables tab, and set its value to 101
  • Type /my_objects.objects[:]{id==$my_ID} in a Raw Messages panel to inspect the object whose id field equals 101
  • Add /my_objects.objects[:]{id==$my_ID}.velocity as a y-axis value in a Plot panel to plot that same object's velocity


  • / – Quickly update numeric variable values